#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int a = 0, sum = 0, cnt = 0;
	int i = 0;
	float average = 0;
	scanf("%d", &a);
	for (i = 0; i < a; i++)
	{
		scanf("%d", &cnt);
		sum += cnt;
	}
	average = sum * 1.0/ a;
	printf("%.2f", average);
	return 0;
}